Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Basic and Diluted:
Net income attributable to UHS	$ 218,351	$ 241,279	$ 752,466	$ 635,245
Less: Net income attributable to unvested restricted share grants	(396)	(790)	(1,609)	(1,987)
Net income attributable to UHS – basic and diluted	$ 217,955	$ 240,489	$ 750,857	$ 633,258
Weighted average number of common shares - basic	82,262	84,672	83,756	85,172
Net effect of dilutive stock options and grants based on the treasury stock method	1,411	575	1,275	415
Weighted average number of common shares and equivalents - diluted	83,673	85,247	85,031	85,587
Earnings per basic share attributable to UHS:	$ 2.65	$ 2.84	$ 8.96	$ 7.44
Earnings per diluted share attributable to UHS:	$ 2.60	$ 2.82	$ 8.83	$ 7.40